Another comparison thread? Well, not really...

A

armoredman

New member
What I refer to is the fact that on another board I was sucked into the old debate over the effectiveness of the 30 Carbine round as opposed to...fill in the blank.
The discussion, which was polite, devolved into a comparison between the 357 Magnum round and the 30 Carbine round, with one critical dimension not accurately represented - the platform.
Postulate; given the 30 Carbine round, while generally held to be inferior to many military issue long gun rounds, is in fact more powerful, (FPS/Foot pounds energy), than a .357 Magnum round out of a revolver, is it possible that the same might NOT be true if they were both fired from the same general platform, i.e., revolvers and long guns?
Yes, it was late, and I was tired, but it seemed like a good idea at the time...
 
The 30 Carbine round is comparable to the 357 if the 30 Carbine is fired from a carbine and the 357 is fired from a revolver. If both are fired from carbines of equal barrel length, the 357 would be more powerful due to it's ~50% greater bullet weight and greater frontal area.
 
I've found over the years the attraction to those .xx versus .yyy threads has waned for me and I now ignore them for the most part, as they are similar to having my grand-daughters over and watching "Tangled" for the 4000th time.
 
A quick check of an old Speer manual shows one load from a 7.5" Blackhawk .30 carbine 110gr bullet hitting 1400fps.

Same book, .357, Ruger 6" barrel, 110gr bullet, three loads topping 1700fps.

That should tell you all that is needed about which one is "more powerful".

Compare the .30 carbine, from a carbine with .357 from a pistol, and its close, but the .357's heavy bullet capability (and bullet design) gives it an edge in effectiveness, if not on paper figures.

Compare both from pistols, or from rifles, and the .357 is clearly more than the .30 carbine.
 
That's what I was looking for, a straight comparison in similar platforms, thank you.
Now I have to wonder, is there a way to increase that 30 Carbine effectiveness...
A necked down bottleneck cartridge version, with a .224 bullet? :eek: Sorry, been cooped up at home to long, cabin fever manifests itself in odd ways...:rolleyes:
 
The 30 Carbine round is comparable to the 357 if the 30 Carbine is fired from a carbine and the 357 is fired from a revolver. If both are fired from carbines of equal barrel length, the 357 would be more powerful due to it's ~50% greater bullet weight and greater frontal area.
Click to expand...

Right. Although perhaps slightly counter-intuitive, the .357 mag gains a LOT from rifle barrel. Buffalo Bore 158s can scream out of an 18" bbl at over 2K fps, and 180s at what, almost 1900? Way more than pistol counterparts. So you are exactly right. Give me a .30 carbine rifle over a .357 mag pistol, but a .357 mag rifle over a .30 carbine rifle, for sure.
 
Sort of Peetza, but just neck down the 30 Carbine so the magazine still works, bolt still works, just replace the barrel. Might be an interesting experiment that someone HAS to have tried in the years this baby came out.
 
Now I have to wonder, is there a way to increase that 30 Carbine effectiveness...
A necked down bottleneck cartridge version, with a .224 bullet?
Click to expand...

MMJ -5.7mm aka 5.7MMJ and .22 Spitfire.

introduced in 1963 (the same year the US released carbines for civilian sale and commercial ammo companies began loading .30 carbine).

Designed my Col Melvin M. Johnson, the same fellow responsible for the Johnson rifle and light machinegun.

Necked down .30 carbine case, offered in converted carbines. ballistics are a 40gr @ 3000fps and a 50gr @ 2700fps.

Not quite a .223, but not too shabby, all things considered.
 
I knew someone had to make it. Lemme guess, never took off because of mountains of surplus 30 Carbine ammo, and nobody makes ammo, bullets OR barrels for it now, either.:(
 
Read a thread about it elsewhere, looks like an interesting cartridge and rifle - now lets see that cartridge mated to a subgun for some real fun. :) :cool:
 
Yep. Wasn't it called the 5.7 Johnson Spitfire?

There are some M1 carbine clones out there in this chambering. Interesting idea. There's almost nothing new under the sun.

Say, that reminds me...Note to self: get that RIA .22 TCM pistol you've been wanting. :)
 
I knew someone had to make it [22 Johnson Spitfire]. Lemme guess, never took off because of mountains of surplus 30 Carbine ammo, and nobody makes ammo, bullets OR barrels for it now, either.
Click to expand...

The 22 Johnson never took off because it was a wildcat that involved buying and installing a new barrel. Ammo was an advanced handloading proposition that involved necking down cases and fireforming. Then when fired the gun tossed the fruits of your labors into the weeds.

.224 bullets are readily available, but ammo never was commercially available, at least not from any of the major manufacturers. Barrels aren't available because the cartridge never caught on, for the reasons listed.

It's not likely to come back because M1 carbines are now collector's items and the presence of the 5.7x28 which fills the same niche and is commercially available.
 
I'd like to see it necked down to 6mm or even .25 cal. Maybe even 6.5. Could be interesting if you could get velocities in the 2400-2500 fps range.
 
Cheaper to make, and lighter than the Tommygun. Better range. Not exactly replaced, as both served together for many years. The Tommygun does some things better than the carbine, the carbine does some things better than the Tommnygun.

Remember that the carbine was considered to be a light rifle, despite its pistol class cartridge (ok, on the upper end of pistol class), while the Tommygun was a SMG, firing the standard .45ACP round.

What replaced the Tommygun was the Grease Gun (M3/M3A1), being somewhat lighter, firing the same round, and waay cheaper to make. Even at the height of cost cutting in the production of Tommyguns, they still cost the govt something like $80 or so (IIRC). The Grease Gun was famous for costing (at one time) $17.50 each.

I may be off on the dollar numbers, but essentially the ratio is correct, 4 (or so) Grease Guns cost what a single Thompson did.

The Grease gun was the first gun we used where we applied the lesson the Germans had learned from mechanized warfare. Guns are lost, damaged, destroyed in war at a tremendously higher rate than they wear out.

Prior to WWII, military arms were made the same way sporting arms were, robustly constructed, and intended to last many,many years. Which also means expensive, in both monetary cost and cost in time & skilled labor to make. WWII taught that a cheap gun, that lasts "long enough" is better than an expensive one that lasts a long time for modern combat.
 
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